Poor people spend so much mental energy on the immediate problems of paying bills and cutting costs that they are left with less capacity to deal with other complex but important tasks, including education, training or managing their time, suggests research published on Thursday.

The cognitive deficit of being preoccupied with money problems was equivalent to a loss of 13 IQ points, losing an entire night’s sleep or being a chronic alcoholic, according to the study. The authors say this could explain why poorer people are more likely to make mistakes or bad decisions that exacerbate their financial difficulties.

Anandi Mani, a research fellow at the Centre for Competitive Advantage in the Global Economy at the University of Warwick, one of the four authors of the study, said the findings also suggest how small interventions or “nudges” at appropriate moments to help poor people access services and resources could help them break out of the poverty trap. Writing in the journal Science, Mani said previous research has found that poor people use less preventive health care, do not stick to drug regimens, are tardier and less likely to keep appointments, are less productive workers, less attentive parents, and worse managers of their finances. “The question we therefore wanted to address is, is that a cause of poverty or a consequence of poverty?”

She said the team of researchers, which included economists and psychologists in the UK and the US, wanted to test a hypothesis: “The state of worrying where your next meal is going to come from – you have uncertain income or you have more expenses than you can manage and you have to juggle all these things and constantly being pre-occupied about putting out these fires – takes up so much of your mental bandwidth, that you have less in terms of cognitive capacity to deal with things which may not be as urgent as your immediate emergency, but which are, nevertheless, important for your benefit in the medium or longer term.”